This invention relates to a package for use in encapsulating a semiconductor device, such as a transistor, a large scale integration (LSI) device, a charge-coupled device (CCD), or the like.
As will later be described with reference to a few figures of the accompanying drawing, various types of packages are used to encapsulate a wide variety of semiconductor devices. In other words, each package is selected in consideration of a characteristic and a size of each semiconductor device. Anyway, each package comprises a base member for supporting each semiconductor device and a ceramic frame member attached to the base member so as to surround the semiconductor device. When a ceramic material is used to form the base member, no crack occurs on the base and the ceramic frame members because a thermal expansion coefficient of the base member is substantially equal to that of the ceramic frame member. However, the base member has a tendency to be deformed with an increase of a size of the base member on manufacturing the package. Such deformation can be avoided by the use of a metal base member which serves as a heat sink also. Use of the metal base member often causes cracks to occur on the ceramic frame member due to a difference in thermal expansion coefficients between the metal base member and the ceramic frame member.